 Jean I Count von Flandern, son of Burchard Seigneur von Avesnes and Margaret Countess von Holland.Born May 1, 1218 at Etraeungt, Nord, France, died Dec 24, 1256, 38 years Married Oct 9, 1246 (10 years married) to:  Adelaide Countess von Holland, daughter of Floris IV Count von Holland, Count of Holland and Mechtild von Brabant.Born ± ABT. 1225 at Holland, died 1284, approximately 59 years Child: 1. Jean II Count von HainaultBorn 1247 at Brabant, Brabant, Holland, died Aug 22, 1304 at Valenciennes, Nord, France, 56 or 57 years | |||